Osteomyelitis symptoms, causes and treatment explained

Osteomyelitis is an infection in a bone. It is uncommon, it is usually treatable, and the earlier it is treated the better it tends to go. This guide covers the symptoms to look out for, who is most at risk, how the NHS diagnoses and treats it, what makes an infection chronic, and the honest position on hyperbaric oxygen therapy.

If you have pain, swelling and warmth over a bone together with a high temperature, do not wait for it to settle. Ask for an urgent GP appointment or contact NHS 111 today.

What are the symptoms of osteomyelitis?

The NHS says osteomyelitis usually causes severe pain, most often in the legs, although it can affect other parts of the body. Other symptoms can include:

• swelling of the affected area
• a feeling of warmth over it
• redness of the skin, which may be harder to see on black or brown skin
• a high temperature
• a limp, which is more common in children

The combination the NHS asks you to act on is pain, swelling, redness and warmth over an area of bone, especially if you also have a very high temperature or feel generally unwell.

In people with diabetes the picture can be quieter. The NHS explains that poorly controlled diabetes can cause loss of feeling in the feet, so small cuts go unnoticed and can develop into an infection that spreads to the bone. A foot wound that is not healing, or that looks infected, may be the first sign rather than obvious bone pain.

Symptoms in children

Children do not always describe pain clearly. The NHS advises taking a child to a GP if they do not want to use an arm or leg and seem irritable, and notes that young children do not always get a high temperature with osteomyelitis. Children may also be more likely to develop it after a respiratory infection or chickenpox.

What is the difference between acute and chronic osteomyelitis?

Doctors describe bone infections by how long they have been present and what they have done to the bone.

Acute osteomyelitis develops over days. A StatPearls clinical review says it may come on gradually over a few days but usually shows itself within two weeks, with redness, swelling and warmth at the site. The NHS says that if the infection is treated quickly, within 3 to 5 days of it starting, it often clears up completely.

Chronic osteomyelitis is an infection that has become established. StatPearls marks the turning point as the formation of sequestra: fragments of dead bone that have lost their blood supply. Antibiotics reach dead bone poorly, which is why chronic infections so often need surgery. Complications listed in the same review include abscesses, a sinus tract (a channel that can leak fluid through the skin), fractures through weakened bone and bone deformity.

Refractory osteomyelitis is a further step. A StatPearls review of hyperbaric treatment describes chronic refractory osteomyelitis as infection that has not responded to at least 6 weeks of appropriate antibiotics together with surgical debridement. This small group is where hyperbaric oxygen is discussed, as explained further down.

Who is most at risk of osteomyelitis?

Anyone can develop osteomyelitis, but the NHS says you are more at risk if you have:

• had osteomyelitis before
• diabetes, especially if you also have a foot ulcer
• broken a bone
• been injured and have a wound
• had an infection or recent surgery
• a weakened immune system, for example because of chemotherapy or a condition such as HIV

StatPearls describes three routes bacteria take to reach bone: through the bloodstream from an infection elsewhere, by spreading from nearby skin, soft tissue or a joint, or directly through an injury or operation. It names open fractures, orthopaedic metalwork, and chronic poorly healing wounds in people with diabetes, peripheral vascular disease or peripheral neuropathy among the high-risk situations.

Diabetes and the foot

The NICE guideline on diabetic foot problems (NG19) tells clinicians to think about osteomyelitis in anyone with diabetes who has a local infection, a deep foot wound or a chronic foot wound. It also warns that osteomyelitis may be present despite normal inflammatory markers, X-rays or probe-to-bone testing. If you have diabetes and a foot wound is not improving, ask your GP, practice nurse or podiatrist to look at it rather than waiting.

When should you get urgent help?

Ask for an urgent GP appointment or contact NHS 111 if, as the NHS advises, you have:

• pain, swelling, redness and a warm sensation over an area of bone
• a very high temperature, or you feel hot, cold or shivery, and feel generally unwell
• had osteomyelitis before and think the symptoms have come back

If you have diabetes, NICE NG19 treats some foot problems as limb-threatening or life-threatening and says they need immediate referral to acute hospital services. Its examples include an ulcer with fever or any signs of sepsis, and clinical concern about a deep-seated soft tissue or bone infection. Other active diabetic foot problems should be referred to a specialist foot service within 1 working day.

The NHS warns that osteomyelitis that is not treated quickly can cause serious long-term problems, including permanent damage to the bone.

How is osteomyelitis diagnosed?

The GP will examine the area and may arrange tests. According to the NHS, you might need a blood test, or to go to hospital for an X-ray, CT scan or MRI scan. Some people need a biopsy, where a small sample is taken from the bone and sent for testing.

StatPearls adds some useful detail. Blood markers of inflammation can help but are not specific to bone infection. MRI has the highest combined accuracy of the standard scans and can detect early infection within 3 to 5 days of it starting. A bone biopsy is the test that confirms the diagnosis and identifies the organism, so the right antibiotic can be chosen.

How is osteomyelitis treated?

Antibiotics. The NHS says you will usually take antibiotics for 4 to 6 weeks, and for up to 12 weeks if the infection is severe. Some people start treatment in hospital; others can take antibiotics at home. Finish the course even if you start to feel better. Painkillers help, and a splint may be used to rest a long bone such as an arm or leg.

Surgery. The NHS says an operation is usually needed if pus builds up in the bone, if the infection presses on something such as the spinal cord, or if a long-standing infection has damaged the bone. Removing the damaged bone is called debridement. It can leave a space that needs reconstructing, and sometimes more than one operation is needed, occasionally using muscle and skin from another part of the body.

Managing the underlying problem. For people with diabetes, NG19 sets out standard care for foot ulcers, including offloading pressure, controlling infection and blood supply, and wound care, delivered through a specialist foot service.

Does hyperbaric oxygen therapy help osteomyelitis?

Hyperbaric oxygen therapy (HBOT) means breathing concentrated oxygen in a pressurised chamber. The reasoning for trying it in bone infection is that the white blood cells that kill bacteria need oxygen, and infected bone is often short of it. The evidence is thinner than the reasoning.

• A recognised specialist indication. The Undersea and Hyperbaric Medical Society includes refractory osteomyelitis on its list of accepted indications. StatPearls is clear that HBOT is not a substitute for antibiotics; it serves as an adjunctive treatment alongside surgical debridement and culture-directed antibiotics, which remain the mainstays of care.
• Hospital protocols use higher pressures and many sessions. StatPearls describes treatment once a day for 90 to 120 minutes, breathing 100% oxygen at 2 to 3 ATA, with 20 to 40 sessions usually needed.
• No randomised trials. StatPearls states that no randomised trials of HBOT for osteomyelitis have been conducted. A 2018 systematic review analysed 45 studies covering 460 people with chronic osteomyelitis, all previously treated with antibiotics and surgery. Of 419 people with complete data, 308 (73.5%) had a successful outcome with no reported relapse. These were cohort studies and case reports without a comparison group, so they cannot show how many people would have recovered without HBOT. The authors described a potentially beneficial role, especially in refractory cases.
• Not routine. The general StatPearls review of osteomyelitis states that hyperbaric oxygen therapy is not routinely recommended in its treatment.

Our position is plain. HBOT Medics uses a single-person soft-shell chamber at 1.5 ATA. That is not the protocol used for refractory osteomyelitis, so the results above cannot be carried over to sessions here. An active or suspected bone infection needs your GP and the hospital teams who manage it. If those specialists feel adjunctive hyperbaric oxygen is worth considering for a stubborn infection, that is a conversation for a hospital hyperbaric unit working at the pressures described above.

Our page on non-healing wounds explains how we think about slow wounds alongside proper wound care, and our chamber page sets out what 1.5 ATA can and cannot be compared with. To understand the treatment itself, read what hyperbaric oxygen therapy is, and who HBOT is not suitable for.

The short version

Pain, swelling, warmth and redness over a bone, especially with a fever, needs an urgent GP appointment or a call to NHS 111. If you have diabetes, a foot wound that is not healing is a reason to get checked promptly. Osteomyelitis is treated with weeks of antibiotics and sometimes surgery. Hyperbaric oxygen is a specialist addition for a small number of stubborn infections, with limited evidence behind it, and it never replaces that care.